In general terms, the field of the invention is that of motor vehicle headlights. Within this field various types of headlights are known, among which can essentially be found the following:                parking lights, of low intensity and short range;        passing or dipped beam lights, having a stronger intensity and with a range in the region of 70 metres along the road, which are used essentially at night, the distribution of their light beam being such that it avoids dazzling the driver of a passing vehicle;        long range cruising lights, and complementary lights of long range type, which have a zone of vision along the road in the region of 200 metres, and which have to be extinguished when passing another vehicle so as not to dazzle its driver;        improved lights of the dual function kind, which combine the functions of a passing light and a cruising light by incorporating a removable mask or shield;        foglights.        
The association in accordance with the invention between a lighting element and a complementary module may be performed with any one of these types of light. The complementary module may for example, in this connection, contain an electronic printed circuit of the Light Control System (LCS) type, which serves for management of so-called complex functions (FBL, DBL, DRL, Cordy etc.) for the light with which the electronic printed circuit is associated. The complementary module may also include a printed control circuit for governing a mechanical element of the actuator type. Nevertheless, the invention will be particularly described in the context of a headlight apparatus of the passing beam type, with a complementary module of the ballast type.
In the context of the invention, a ballast is a particular complementary module which is preferably contained in a headlight apparatus of the dipped beam or passing type which uses a discharge lamp as its light source. More particularly, in the invention reference is made to ballasts with a Xenon system, also referred to as high intensity discharge (HID) systems, which are necessary to create and maintain in force an electrical arc which is used in xenon lamps. An electronic module sets up a high voltage in the ballast to produce the electric arc in the light source used. In this type of light, a complementary module of the ballast type is therefore indispensable in order to provide the energy needed for proper functioning of the headlight.
However, integration of such a module within the headlight apparatus has to be done while having regard to the following restrictive conditions:                it must be done using as simple an assembly (fitting) operation as possible;        it must be as small as possible in size;        in order to avoid any damage to the elements contained in the ballast, it must withstand high temperatures which may occur during operation of the headlight apparatus;        it must take into account the need for transmission of electrical signals between the various elements of the headlight apparatus;        the association between the lighting element and the complementary module must not involve sealing problems in connection with any of its components.        